“Can you see me?” In the age of video calls, this has become a common question. But when posed to philosopher David Chalmers, it takes on a deeper significance. Regarding the basic version of virtual reality (VR) in which we’re having our conversation, Chalmers suggests that “some very conservative philosophers would say no, I am merely seeing a pattern of pixels on a screen and I’m not seeing you behind it.” But Chalmers has a different view: “Yes, I’m seeing you perfectly,” he replies, covering both meanings with his answer. His seemingly simple claim has implications not just for the possibilities of virtual reality, but the nature of actual reality, too.
Chalmers is one of the best-known philosophers of the 21st century. Although his latest book, Reality+, is the first aimed squarely at the general reader, he’s already managed to cross over from academia, helped hugely by his essay “The Matrix as Metaphysics,” which he wrote for the movie’s official website in 2003. He also inspired Tom Stoppard’s play about consciousness, The Hard Problem. Chalmers’s easy manner, scruffy attire and (for many years) unkempt long hair have led him to be plausibly labelled a “rock-star philosopher.”
His reputation is built less on his own theories than on his pithy way of capturing arguably the biggest problem in philosophy today. Chalmers distinguished between the “easy” and “hard” problems of consciousness. The “easy” problem is to map out which brain processes give rise to which mental states. This is “easy” only in the sense that it raises no deep conceptual questions. The “hard” problem of consciousness, in contrast, is how a lump of organic matter, no matter how complex its organisation, can ever give rise to the experience of self-awareness. This is now known as “Chalmers’s Hard Problem,” though it predates his baptism of it.
Now Chalmers has turned to the question of whether a fully immersive, perfectly simulated virtual reality—call it Full VR—would be a genuine form of reality or an alternative to it. His book is well timed: in October 2021, Mark Zuckerberg announced that Facebook is working on building the metaverse—a “completely immersive… embodied internet,” in which you can join meetings or have dinner with friends using a personal avatar in a 3D online environment.
While Zuckerberg anticipates a virtual utopia, others fear a dehumanising end of reality. Who is right largely rests on the answer to an old philosophical question: what is reality? What is new about “technophilosophy,” as Chalmers calls his approach to philosophy in Reality+, is that first, we’re applying philosophy to novel technologies; and second, we’re using those technologies to help us think differently about perennial philosophical issues. Technophilosophy is old-school metaphysics, rebooted.
Take my opening question: can you see me? Chalmers argues that if you think you’re not seeing someone when you Zoom them, by the same logic, we never see each other. We have long ago given up the naive idea that we can perceive things directly, unmediated. We know that everything goes through sense perception and the exact form of how it appears to us is constructed in the brain: all perception is mediated. So the only meaningful sense in which I really do see or hear you, even in real life, is that what I am seeing and hearing is in some importantly truthful way causally related to you.
New technology can change the causal chain. But if it preserves the critical relations, it’s still facilitating the perception of real persons and things. Take a phone conversation. “Maybe the very first time someone used a telephone they said, ‘I’m hearing a projection of their voice, I’m not hearing them directly,’” says Chalmers. “But the moment telephones actually entered our lives, people were innocently saying: ‘I can hear you.’ One thing we find with the progression of technology is that these concepts just very naturally extend themselves.”
Chalmers thinks we’re going through another such extension. Even with our primitive VR, it is already “very natural to say we perceive virtual objects inside a virtual reality.” The obvious objection is that whatever you see in virtual reality is, by definition, not real. A virtual cat is not a real cat. In one sense, Chalmers agrees. It’s not a flesh-and-blood, organic, biological cat; but it is a real virtual cat. This isn’t semantic quibbling. Think about how science has changed our understanding of how what we see relates to fundamental reality. Quantum physics has shown us that what underpins the apparently solid objects of our world is largely empty space. It isn’t that things like cats and tables don’t exist; they do. It’s just their appearances do not reveal their most basic nature. In a virtual world, virtual objects would be similarly real, even though at their most basic level they are “just” bits of information.
Where you side in these debates depends a lot on how you define “real.” Chalmers argues that by “real” we can mean one of five things: it exists; it has causal powers; it is mind independent; it is non-illusory; and it is a real instance of the thing it is taken to be. He argues that a fully immersive VR which was indistinguishable from the inside from real life would tick at least four boxes. Take the example of a digital dog. First, whatever you think digital dogs are, they certainly in some sense exist. Second, in Full VR, a virtual dog has causal powers: if it bites, it’ll hurt. Third, they are mind independent: if you leave the virtual world the dog’s still sniffing around in it.
While Zuckerberg anticipates a virtual utopia, others fear a dehumanising end of reality
Less obviously, a digital dog is—or at least can be—non-illusory. You might think that VR is by its nature illusory, since its whole raison d’être is to make the merely digital seem real. But Chalmers argues the concept of “cognitive penetration” shows this needn’t be so. When you look in the rear-view mirror of a car, does what you see appear to be in front of, or behind, you? Strictly speaking, it appears in front of you. That’s why an animal will typically go up to something it sees in a mirror as though it were behind the glass. But because we know it is a reflection and we have got used to this, we actually see it as behind us.
Chalmers thinks something similar could happen in a virtual world. So when he went into a VR lab and was asked to step off a plank above the Grand Canyon, “I wanted to tap the ground first with my foot, just to just to make sure.” But after a while “you rapidly get used to the affordances. You can step off the plank and you can walk over to the other side of the Canyon. You’re just walking on air, you just get used to it.” Over time, the virtual nature of such a world becomes something “you just kind of bake into your perception of reality.” It would feel no more illusory than the sun seeming to rise when we know it’s the Earth that’s moving.
The only test that Chalmers thinks Full VR might not pass is that although a digital dog is real, you might say it is not a real dog, because real dogs are biological. It’s a bit like saying that oat milk is real, but it’s not real milk.
Chalmers argues that because Full VR passes four out of his five tests, we can say it is “at least 80 per cent real.” But four out of five isn’t necessarily the same as 80 per cent. If I only fulfil four out of the five criteria for being a doctor, I’m not 80 per cent doctor; I’m not a doctor at all. So a lot rests on how important the distinction is between real digital things and real things, period.
Many people will be drawn to Reality+ for its intuition-defying arguments that we could already be living in a simulation and not know it; or that in the future we could upload ourselves to VR world which would be as real—and as enjoyable—as biological life. To me, these arguments seem to depend too much on probabilities that we’re in no position to assess. Would it ever be possible to have enough computational power and electricity to create a virtual world as rich and immersive as our current physical one? Something as comparatively basic as the cryptocurrency Bitcoin, for example, uses up 0.5 per cent of all the world’s electricity.
Chalmers agrees these problems should be taken seriously, but still puts the possibility that we will create Full VR at at least 50:50. On the question of the power resources needed, he points out that although fundamental physical restraints mean that “no finite universe can perfectly simulate itself in every detail,” that doesn’t matter because Full VR doesn’t need that. “Universes merely need to simulate universes simpler and smaller than themselves. Maybe, for example, some portion of some faraway star’s energy could be used to simulate roughly what’s going on on the Earth and a small area around it.”
Chalmers argues that an infinite universe could fully simulate a finite one such as ours. And if our universe was a perfect simulation, we’d have no way of knowing. Many take this possibility seriously but why, I ask, if our world is such a simulation, is it so awful? If it’s the product of blind evolution, then poverty, disease, human cruelty and so on are only to be expected. If it’s the product of intelligent design, then the beings behind it are both incredibly smart and incredibly sadistic. They could have created a world of abundance and safety. Instead, they created a world of cancer, MS and Ebola, not to mention torture and rape.
Just about any technology has utopian potential and also has dystopian potential
Chalmers is interested in this spin on the argument from evil against God’s existence, and other questions of what is called “simulation theology.” But he doesn’t buy it.
“It all depends on the nature and the motives of the simulator and there are thousands of different possible motives,” he says. “Our world is not all bad by any means. It’s got some awful things, it’s got some wonderful things. They may take the view that creating a net balance of good things over bad things is sufficient reason to create the world… the bottom line is I don’t think there’s any special reason to think that our simulators are going to be ethically perfect creatures. They could be as ethically imperfect as the rest of us.”
Even if Full VR is a possibility, should we risk creating it? Techno-utopians tend to radically overestimate our capacity to reengineer the fundamentals of human nature and society. Chalmers sees the worry. “If you think that social media is a problem now because Facebook is running the newsfeed, wait ’til these social media corporations are running our day-to-day life in virtual worlds.”
But ultimately, he is sanguine. “With any technology there are hubristic utopians,” he acknowledges. “Just about any technology has utopian potential and also has dystopian potential, and I’m making no particular predictions. Where we'll end up will almost certainly going to be a mix of the two. I like the analogy with the internet. I mean, yeah, it had utopian potential, some of which has been achieved. But it’s also had some awful consequences.”
Perhaps the most common visceral reason we have for resisting virtual life is that it is indubitably artificial and many of us feel we want to be in touch with nature. Chalmers thinks that’s "a reasonable value but a perfectly optional one. I’m living my life here in New York City—not terribly natural, but a meaningful life for all that.”
In his book, Chalmers doesn’t make predictions about how quickly he expects Full VR to become a reality. He tells me: “in general people tend to overestimate advances in the short term and underestimate them in the long term. So I suspect that in the short term there are going to be many obstacles and delays and glitches.” He adds: “it wouldn’t surprise me if it’s two or three decades until we have really seamless virtual realities used as a matter of course by everyone.”
How convinced you are by the possibilities of a good life in VR may depend more on your age than the strength of Chalmers’s arguments. “There’s a generational thing here. We’re both gradually getting on but there are young people who are just coming through now in their teens. It’s just so natural for them to be interacting with a digital world and to treat it as real, and I think maybe for people in this situation, the idea that reality is a simulation is nowhere near as foreign as it might have been for you and me.”
Not so long ago, the kinds of scenarios Chalmers discusses in his book could have been ignored as speculative science fiction or interesting thought-experiments of no practical import. In the age of the metaverse, though, we can no longer afford to ignore them. “This technology is going to continue to raise philosophical questions. They’re not going to go away.”
